The present invention relates to a high viscous substance composition and its purified high viscous substance which are produced by cultivating a microbe belonging to genus Klebsiella and which are useful as an additive such as a thickening agent and/or an emulsion stabilizer for food, medicine, etc., and a process for producing such a high viscous substance composition and its purified high viscous substance.
The aforementioned high viscous substance will be referred to as "a high viscous substance BS-1" hereinunder.
As high viscous substances which are produced by a microbe, polysaccharides such as xanthan gum which is produced by Xanthomonas campestris, dextran which is produced by Leuconostoc mesenteroides and pullulan which is produced by Aureobasidium pullulans are well known. On the other hand, carrageenan, tragacanth gum, etc. are known as high viscous substances obtained from a plant. These substances are now in wide use in the fields of food and medicine as a food additive such as a thickening agent, a dispersant and a modifier and, further, as a plasma substitute.
These substances have, however, disadvantages in that a comparatively high concentration must be added to obtain the intended effect and in that they are poor in long-term stability. Therefore, development of a high viscous substance which exhibits a high viscosity even in a low concentration and has excellent stability has been in demand in various fields including the fields of food and medicine.
The present inventors cultivated and tested various kinds of microbes in order to obtain an excellent high viscous substance which is usable in a field of a wide range. As a result, it has been found that it is possible to produce an excellent high viscous substance composition and its purified high viscous substance which exhibit a high-viscosity even in a low concentration by cultivating a strain of Klebsiella pneumoniae which belongs to genus Klebsiella. The present invention has been achieved on the basis of this finding.
The first object of the present invention is to provide a novel high viscous substance BS-1 composition which is obtained by cultivating a microbe belonging to genus Klebsiella and which exhibits a high viscosity and good stability by the addition of a comparatively low concentration of the substance composition.
The second object of the present invention is to provide a novel high viscous substance BS-1 which is obtained by purifying the aforementioned high viscous substance BS-1 composition and which exhibits a high viscosity and good stability by the addition of a comparatively low concentration of the substance.
The third object of the present invention is to provide a process for producing the aforementioned high viscous substance BS-1 composition, comprising cultivating a microbe belonging to genus Klebsiella.
The fourth object of the present invention is to provide a process for producing the aforementioned high viscous substance BS-1, comprising purifying the aforementioned high viscous substance BS-1 composition.
The fifth object of the present invention is to provide a thickening agent and/or an emulsion stabilizer which contains the aforementioned high viscous substance BS-1 composition or the aforementioned high viscous substance BS-1 as an active ingredient.
The sixth object of the present invention is to provide a process for increasing the viscosity of food, medicine, cosmetic, chemicals or the like and/or stabilizing the emulsion thereof by adding the aforementioned high viscous substance BS-1 composition or the aforementioned high viscous substance BS-1 thereto.